Sloped concrete roof and eave system

ABSTRACT

A sloped concrete roof and eave method and system is disclosed which can be used in commercial or residential construction. The sloped concrete roof and eave of the present invention may be formed using several concrete construction methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and claims the benefit of U.S.Provisional Application No. 60/846,005, filed Sep. 20, 2006, entitled“Sloped Concrete Roof and Eave System,” which is hereby incorporated byreference.

BACKGROUND

Roof systems are all sloped or pitched to allow water to run off anddrain, while providing shelter. Roof slopes fall into two categories.One category is roofs having a small slope, such as a ⅛″ rise per footslope for flat roofs, and the other category is for roofs with a muchgreater slope, such as a 3″-12″ rise per foot slope.

Roofs in the first category, small slope roofs, typically use a truss orjoist system for support. The roofs in this category are then typicallyfinished using plywood, insulation, built up roofing membrane andgenerally have parapet walls. Commercial construction of such smallslope roofs may have a poured concrete slab over metal decking which isplaced above the roof joist or truss system.

When a building design calls for a roof in the second category (i.e.having a larger slope, such as 5″ rise per foot), however, concrete slabis generally not considered for a umber of reasons. The methods forforming such roofs and the structural requirements of such roofs can bevery costly and time consuming. One such obstacle is the horizontalforce exerted on the walls from the sloped roof. Special supports andconnectors have been devised to address this issue in known roofingsystems. Presently, because of these issues, buildings requiring largeroof slopes are typically built using either a roof truss or roof raftersystem, which is generally of wood construction.

Wood roof systems, though, are especially susceptible to damage in astorm or hurricane due to the strong winds of the storm. The wind forcesthat storms can generate may exceed the structural design of a wood roofsystem. This can result in significant roof damage and possibly rooffailure. Also, because wood deteriorates, such deterioration canexacerbate the situation and heighten the possibility of roof damageduring a storm. Also, because of such deterioration, wood roofingsystems eventually need to be replaced as well.

Steel truss or joist systems are stronger than wood and typicallyprovide better protection against the damage that such storms can cause.However, roof finishes do not differ of those of wood and steel trussroof systems and are still susceptible to damage during storms orhurricanes, and such damage can compromise the integrity of thebuilding. Concrete roofing systems are an alternative, but to date,these concrete roof systems have only been used on a limited basis andare not favorable for production housing construction. Current concreteroof designs are limited by their structural design and also by themanner in which they are made or formed. This process is typically slowand cumbersome. These obstacles make concrete roof systems expensive tobuild and difficult to use in production housing construction or inother facets of construction.

Accordingly, there is a need for a concrete roofing system that can beproduced more effectively and efficiently which can be used in aproduction housing construction environment, with benefits forcommercial and residential construction as well.

SUMMARY

According to one aspect of the present invention, a building system witha sloped concrete roofing and eave includes a number a plurality offloor slabs; a number of concrete sidewalls having a formed concreteeave formed thereon, wherein the concrete sidewalls are connected to theplurality of floor slabs; and a concrete roof, wherein the concrete roofis integrated with the formed concrete eave. The sidewalls, the concreteeave and the concrete roof of the building system may be poured inplace, integral with one another. The concrete roof of the buildingsystem may include a truss system, a number of purlin members or anumber of polystyrene panels. The concrete eave of the building systemmay also be poured in place with the sidewalls and the concrete roof maybe precast, wherein the precast roof is connected to the poured in placeconcrete eave.

According to another aspect of the present invention, a method forconstructing a building with a sloped concrete roof and connected eaveincludes providing an eave form, a sidewall form and a roof supportform, wherein the eave form, sidewall form and roof support forminterconnect with one another to allow the free flow of concrete betweenthe forms. The method also includes pouring concrete into the roofsupport form, the eave form and the sidewall form; and allowing theconcrete to cure to an appropriate stripping strength to form a slopedconcrete roof, a concrete eave and a concrete sidewall. The method mayalso include providing a roof truss system, wherein the roof supportform is supported with the roof truss system or wherein the roof supportform is supported with a hydraulic lift. The method may also includeusing a tunnel construction system, insulated concrete form system,handset form system or gang form system to support the roof supportform, the eave form and the sidewall form. The roof support form of themethod may include purlin members or polystyrene panels. The method mayalso include a precast roof, eave or sidewall. The method may alsoinclude the use of a strap connector, wherein when the concrete ispoured and the concrete cures, the strap connector connects the rooftruss system and the concrete eave.

DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with regard to the followingdescription, appended claims and accompanying drawings where:

FIG. 1 is a plan view of a single family building with an embodiment ofa sloped concrete roof of the present invention;

FIG. 2 is a plan view of a multi-family building with an embodiment of asloped concrete roof of the present invention;

FIG. 3A is a perspective view of an embodiment of a roof of the presentinvention with portions of the roof removed for illustration purposes;

FIG. 3B is a cross section along the line 3B-3B of FIG. 1, illustratinga cast-in-place roof and eave using aluminum forms and a truss system;

FIG. 3C is a cross section along the line 3C-3C of FIG. 1, illustratinga cast-in-place roof and eave using aluminum forms and a truss system;

FIG. 3D is a section detail of a cast-in-place roof and eave usingaluminum forms and a truss system;

FIG. 4A is a cross section along the line 4A-4A of FIG. 2, illustratinga cast-in-place concrete roof and cave in a tunnel form constructionsystem using a roof truss system;

FIG. 4B is a cross section along the line 4B-4B of FIG. 2, illustratinga cast-in-place concrete roof and eave in a tunnel form constructionsystem using a roof truss system;

FIG. 4C is a section detail of the cast-in-place concrete roof and eavein a tunnel construction system using a truss system;

FIG. 4D is a section detail of the cast-in-place concrete roof and eavein a tunnel construction system using a truss system table with thepolystyrene panels running perpendicular to the perimeter wall;

FIG. 5A is a cross section of a two story building similar to the crosssection in FIG. 4A illustrating a cast-in-place concrete roof and eavein a tunnel form construction system using a hydraulic table;

FIG. 5B is a cross section of a two story building similar to the crosssection in FIG. 4B illustrating a cast-in-place concrete roof and eavein a tunnel form construction system using a hydraulic table;

FIG. 5C is a section detail of the cast-in-place concrete roof and eavein a tunnel construction system using a hydraulic table;

FIG. 5D is a section detail of the cast-in-place concrete roof and eavein a tunnel construction system using a hydraulic table with thepolystyrene panels running perpendicular to the perimeter wall;

FIG. 6A is a cross section of a two story building similar to the crosssection in FIG. 4A illustrating precast roof panels and a cast-in-placeeave in a tunnel form construction system;

FIG. 6B is a cross section of a two story building similar to the crosssection in FIG. 4B illustrating a precast roof panel and a cast-in-placeeave in a tunnel form construction system;

FIG. 6C is a section detail of the precast concrete roof panel andcast-in-place concrete eave in a tunnel construction system;

FIG. 7 is a section detail of a cast-in-place concrete roof and eaveusing insulated concrete forms and truss system;

FIG. 8 is a section detail of a cast-in-place concrete eave and wallusing insulated concrete forms and precast concrete roof panels andtruss system;

FIG. 9 is a section detail of a cast-in-place concrete eave and wallusing aluminum forms and precast concrete roof panels and truss system;and

FIG. 10 is a section detail of a precast concrete roof and eave andtruss system.

DETAILED DESCRIPTION

The embodiments of the invention disclosed herein include acast-in-place and pre-cast concrete roof, eave and wall system. Theconcrete roof and eave system embodiments include the use of, but arenot limited to using, steel or aluminum forms, polystyrene panels andtruss systems. In these embodiments, the foundation system, generallyconcrete footings and/or monolithic concrete floor slabs, are set. Ifmore than one story is being built, the lower level floors and walls areset braced and shored. Once the last floor is set, the forms are placedalong with a truss system to serve as a temporary shoring device. Afterthe trusses and forms have been set and secured, polystyrene panels andsteel reinforcements are placed and concrete is poured to create theroof slab, concrete eave, and walls. When the concrete is cured, theforms are removed. The roof can now be finished using conventionalshingles, tiles or an aluminum roof system.

Referring to FIG. 1, a roof 10 of an embodiment of the invention isdepicted. The roof 10 is typically supported by bearing walls 12, as itis in this embodiment. The roof 10 of this embodiment includes hips 14,ridges 16, valleys 18, gables 20 and eaves 22. The eave 22 is the partof the roof 10 that extends past the walls 12. Referring now to FIG. 2,a multi-family residence is illustrated. In multi-family residences,units are generally divided by party walls 24.

Referring to FIGS. 3A-3D, a preferred embodiment of the invention isdepicted. FIGS. 3A-3D illustrate a monolithic cast-in-place concreteroof 10, eave 22 and wall 12 arrangement formed using concrete wallforms 50, 52 (FIG. 3B) (industry termed handset or gang forms) alongwith an eave form 54. A two story building is illustrated, but it shouldbe understood that the design is not limited to single or two storybuilding. Referring specifically to FIG. 3B, in this embodiment, lowerlevel walls 12 and floors 26 are first poured and cured. Then, upperwall steel reinforcements are placed. Interior and exterior wall forms50, 52 and eave forms 54 are then set and braced. All wall openings areblocked during the setting of the forms 50, 52, 54. In this embodiment,a pressure treated wood blocking 55 (FIG. 3D) is secured to the eaveform 54 and used as a nailer for drip edge or for gutter installation.

Once all forms 50, 52, 54 are set and braced, roof trusses 60 are set ontop of the wall forms 50, 52. The truss 60 has a bottom chord 62 whichcan be used as a collar tie to balance the horizontal thrust of theconcrete roof 10. In this embodiment, this is done by attaching readilyavailable strap connectors 64 to the bottom chord 62 and positioning thestrap connectors 64 so that when the concrete is poured, the strapconnectors 64 are embedded into the concrete wall 12 and eave 22.Blocking inserts are placed between the trusses 60 to close anyopenings. In this embodiment, purlin members 66 are perpendicularlyplaced on top or between the roof trusses 60 for added rigidity. Thepurlin members 66 also provide for the placement of polystyrene panels68 on the roof 10. In this embodiment, polystyrene panels 68 are placedand screwed to the purlin bracing members 66. The purlin bracing members66 hold the panels 68 in place so a construction crew can setappropriate steel reinforcements.

At this point in the process, all bracing and shoring posts are placed.Next, in this embodiment, flowable concrete is pumped into the forms 50,52, 54 to form the remaining wall portions 12, the eave 22 and a roofsurface 70. Once poured, the concrete is then properly sloped andsmoothed in a conventional manner, using screed boards and masonrytools. After the poured concrete has cured, all bracings, shoring, andforms are removed, and the building is ready for finishing.

Referring to FIGS. 4A-4D, an alternate embodiment of the invention isdepicted. FIGS. 4A-4D illustrate a monolithic cast-in-place concreteroof surface 10, walls 12 and eave 22 in a tunnel construction systemand truss. Referring specifically to FIG. 4B, once the lower levelfloors 26 and walls 12 have been poured, steel reinforcement bars areset in place for the upper level walls 12. Interior forms 80, includingstackable forms 82, are then placed. Once set in place, the stackableforms 82 are elevated as illustrated in FIG. 4B and secured to theopposite forms 82 with form ties. Referring now to FIG. 4C, hingedextension forms 84 and extension support forms 86 are also raised fromtheir resting position and set in place at this time. Exterior forms 88are then set and secured with the interior forms 80 using form ties.Concrete eave forms 54 are then attached directly to the exterior forms88. If adjustments between adjacent eave forms 54 are necessary in thisembodiment, an adjustable support arm 90 is used to make suchadjustments.

In this embodiment, aluminum framed platforms 92 are set above theinterior forms 80. Trusses 60 are then set above the aluminum framedplatforms 92. Horizontal shoring 98 (FIG. 4B) is used for lateralstability. Polystyrene panels 94 are then set and placed runningperpendicular to the party walls 24. The polystyrene panels 94 areplaced in this direction to transfer the structural load to the partywalls 24. (FIG. 4D depicts the polystyrene panels 94 set in a directionrunning perpendicular to the party walls 24.) The polystyrene panels 94are secured to the trusses 60 below.

Steel reinforcement bars are placed as required. Also, a wood blocking55 can be secured to the eave forms 54 to be used as a nailer for dripedges or gutters. Also, it should be noted that the eave molding 96 canhave different patterns and be a removable trim part of the eave form54.

Referring to FIG. 4B, once all of the forms have been set and the otheritems described above are complete, then flowable concrete is pouredinto the eave forms 54 and wall forms 80, 88 and onto the polystyrenepanels 94 to create the roofing surface 70, the eaves 22 and theremaining walls 12. After the concrete has cured to the requiredstripping strength, the aluminum truss platforms 92 are removed. Theextension support forms 86 are lowered against the interior forms 80, asare the extension forms 84. The stackable forms 82 are returned to aresting position as well. The exterior forms 88 and the eave forms 54are detached from the interior forms 80 and removed from the walls 12,24. Finally, the interior forms 80 can be removed from the building andare ready to be reused. The roof 10 is finished using conventionalmethods and materials.

Referring to FIGS. 5A-5D, another alternate embodiment of the inventionis depicted. FIGS. 5A-5D illustrate a monolithic cast-in-place concreteroof in a tunnel construction system using a hydraulic table. Referringspecifically to FIG. 5B, once the lower level floors 26 and walls 12have been poured and cured, steel reinforcement bars are set in placefor the second level walls 12. As with the previously describedembodiment, interior forms 80, including stackable forms 82, are thenplaced. Once set in place, the stackable forms 82 are elevated asillustrated in FIG. 5B and secured with form ties to the opposite forms82. Referring now to FIG. 5C, hinged extension forms 84 and extensionsupport forms 86 are also raised from their resting position and set inplace at this time. Exterior forms 88 are then set and secured with theinterior forms 80 using form ties. Concrete eave forms 54 are thenattached directly to the exterior forms 88. If adjustments betweenadjacent eave forms 54 are necessary, an adjustable support arm 90 isused to make such adjustments.

In this embodiment, a hydraulic table 100 is then raised to a designatedslope. Horizontal shoring posts 98 are set and secured against thestackable forms 82 and the hydraulic table 100 to support the interiorforms against lateral forces. As above, polystyrene panels 94 are thenset in place, in a direction running perpendicular to the party walls24. As described above, the polystyrene panels 94 are placed in thisdirection to transfer the structural load to the walls 24. (FIG. 5Ddepicts the polystyrene panels 94 set in a direction runningperpendicular to the party wall 24.)

Once all the forms are set, steel reinforcements are placed for the roofsurface 70 and eave 22. A wood blocking 55, as before, can be secured tothe eave form 54 to be used as a nailer for drip edges or gutters. Also,it should be noted that the molding 96 can have different patterns andbe a removable trim part of the eave form 54.

The next step is to pour concrete into the forms 54, 80, 88 and over thepolystyrene panels 94 to create the roofing surface 70, the eaves 22 andthe remaining walls 12. After the concrete has cured to a strippingstrength, the horizontal shoring posts 98 are removed. The extensionsupport forms 86 are lowered against the interior forms 80, as are theextension forms 84. The stackable forms 82 are returned to a restingposition as well. The exterior forms 88 and the eave forms 54 aredetached from interior forms 80 and removed. The interior forms 80 canbe removed from the building and are ready to be reused. The hydraulictable 82 is left in place for temporary shoring of the concrete roof 10.The roof 10 is finished using conventional methods and materials.

Referring now to FIGS. 6A-6C, another alternate embodiment of theinvention is depicted. FIGS. 6A-6C illustrate a roof system having aprecast concrete roof panel and a cast-in-place concrete eave and wallusing tunnel construction. Referring specifically to FIG. 6B, once thelower level floor 26 and the walls 12 have been poured, steelreinforcement bars are set in place for the second level walls 12.Interior forms 80, including stackable forms 82, are then placed. Onceset in place, the stackable forms 82 are elevated as illustrated in FIG.6B and secured to the opposite forms 82 with form ties. Exterior forms88 are then set and secured with the interior forms 80 using form ties.Concrete eave forms 54 are then attached directly to the exterior forms88. If adjustments between adjacent eave forms 54 are necessary, anadjustable support arm 90 is used to make such adjustments.

Referring now to FIG. 6C, a support form 108 is secured by using aperforated vertical bar 104 or form tie that is secured onto the supportform 108. For forms made of aluminum or steel, an optional channel 106may be used. A spreader bar 110 is used on a preset spacing to keep thesame distance between the eave form 54 and the support form 108 and issecured with the vertical bar 104 or form ties. A horizontal shoringpost 98 (FIG. 6B) is set and secured against the stackable forms 82 tosupport the interior forms 80 against lateral forces. A wood blocking 55can be secured to the eave form 54 to be used as a nailer for drip edgesor gutters. The molding 96 can have different patterns and be aremovable trim part of the eave forms 54.

Once all of the above has been completed, concrete is poured into theforms 54, 80, 88 to form the walls 12, 24 and eaves 22. After theconcrete has cured to a stripping strength, the support form 108 can beremoved followed by removing the spreader bar 110. The horizontalshoring posts 98 can be removed, followed by lowering the stackableforms 82 into the resting position. All the forms can now be removed.Precast concrete roof panels that form the roofing surface 70 are thenhoisted into place and secured to the walls 12. The roof 10 is finishedusing conventional methods and materials.

There are various wall forms made of different materials such as wood orfoam such as Insulated Concrete Forms (ICF) that can be used inpracticing this invention. FIGS. 7-10 illustrate further alternativeembodiments. FIGS. 7 and 8 illustrate roofing systems where ICF forms108, 110, 112 are used. The forms are held together with form ties 106.FIG. 9 illustrates an embodiment where the eave 22 is cast in placeusing aluminum forms 114, and the roof 10 is precast. FIG. 10illustrates an embodiment where the eave 22 and the roof 10 are bothprecast. For forms that cannot withstand the pressure of concrete beingpoured continuously into the walls and the roof, the roof may be pouredseparately from the walls. The eaves may be poured with the walls alongwith a recessed pocket to receive the trusses and minimize labor.

Precast concrete panels may substitute the cast-in-place walls or roofin any of the embodiments described above and vice versa. A ledge may berecessed into the inside of the eave to allow bearing of trusses andprecast concrete panels. All collar tie strap and connectors arepreferred to be embedded into the eave during casting or precastingphase of the walls.

While the invention has been discussed in terms of certain embodiments,it should be appreciated that the invention is not so limited. Theembodiments are explained herein by way of example, and there arenumerous modifications, variations and other embodiments that may beemployed that would still be within the scope of the present invention.

1. A building system with a sloped concrete roofing and eave,comprising: a plurality of floor slabs; a plurality of concretesidewalls having a formed concrete eave formed thereon, wherein theconcrete sidewalls are connected to the plurality of floor slabs; and aconcrete roof, wherein the concrete roof is integrated with the formedconcrete eave.
 2. The building system of claim 1, wherein the sidewalls,the concrete eave and the concrete roof are poured in place, integralwith one another.
 3. The building system of claim 2, wherein theconcrete roof includes a truss system.
 4. The building system of claim3, wherein the concrete roof includes a plurality of purlin members. 5.The building system of claim 3, wherein the concrete roof includes aplurality of polystyrene panels.
 6. The building system of claim 1,wherein the concrete eave is poured in place with the sidewalls and theconcrete roof is precast and wherein the precast roof is connected tothe poured in place concrete eave.
 7. A method for constructing abuilding with a sloped concrete roof and connected eave, comprising:providing an eave form, a sidewall form and a roof support form, whereinthe eave form, sidewall form and roof support form interconnect with oneanother to allow the free flow of concrete between the forms; pouringconcrete into the roof support form, the eave form and the sidewallform; and allowing the concrete to cure to an appropriate strippingstrength to form a sloped concrete roof, a concrete eave and a concretesidewall.
 8. The method for constructing a building with a slopedconcrete roof and connected eave of claim 7, further comprising:providing a roof truss system, wherein the roof support form issupported with the roof truss system.
 9. The method for constructing abuilding with a sloped concrete roof and connected eave of claim 7,wherein the roof support form is supported with a hydraulic lift. 10.The method for constructing a building with a sloped concrete roof andconnected eave of claim 7, wherein a tunnel construction system is usedto support the roof support form, the eave form and the sidewall form.11. The method for constructing a building with a sloped concrete roofand connected eave of claim 7, wherein an insulated concrete form systemis used to support the roof support form, the eave form and the sidewallform.
 12. The method for constructing a building with a sloped concreteroof and connected eave of claim 7, wherein a handset form system isused to support the roof support form, the eave form and the sidewallform.
 13. The method for constructing a building with a sloped concreteroof and connected eave of claim 7, wherein a gang form system is usedto support the roof support form, the eave form and the sidewall form.14. The method for constructing a building with a sloped concrete roofand connected eave of claim 7, wherein the roof support form includes aplurality of purlin members.
 15. The method for constructing a buildingwith a sloped concrete roof and connected eave of claim 7, wherein theroof support form includes a plurality of polystyrene panels.
 16. Themethod for constructing a building with a sloped concrete roof andconnected eave of claim 7, further comprising: providing a precast roof.17. The method for constructing a building with a sloped concrete roofand connected eave of claim 7, further comprising: providing a precastsidewall with an integrated precast eave.
 18. The method forconstructing a building with a sloped concrete roof and connected eaveof claim 8, further comprising: providing a strap connector connected tothe roof truss system; prior to pouring the concrete into the roofsupport form, the eave form and the sidewall form, positioning the strapconnector between the roof truss system and the eave form, wherein whenthe concrete is poured and the concrete cures, the strap connectorconnects the roof truss system and the concrete eave.